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JSFR key technology evaluation on fuel handlingsystemYoshitaka Chikazawaa, Atsushi Katoha, Hiroyuki Obatab, Masayuki Uzawac, Kazuhiro Kogad

& Ryo Chishiroe

a Japan Atomic Energy Agency, 4002 Narita, Oarai, Higashi-ibaraki-gun, Ibaraki 311-1393,Japanb Japan Atomic Power Company, 4002 Narita, Oarai, Higashi-ibaraki-gun, Ibaraki311-1393, Japanc Mitsubishi FBR Systems, 2-34-17 Jingumae, Shibuya, Tokyo, Japand Fuji Electric, 1-1, Tanabeshinden, Kawasaki, Kawasaki, Japane Kawasaki Heavy Industries, 1-14-5, Kaigan, Minato-ku, Tokyo, JapanPublished online: 07 Jan 2014.

To cite this article: Yoshitaka Chikazawa, Atsushi Katoh, Hiroyuki Obata, Masayuki Uzawa, Kazuhiro Koga & Ryo Chishiro(2014) JSFR key technology evaluation on fuel handling system, Journal of Nuclear Science and Technology, 51:4, 437-447,DOI: 10.1080/00223131.2014.873360

To link to this article: http://dx.doi.org/10.1080/00223131.2014.873360

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Journal of Nuclear Science and Technology, 2014Vol. 51, No. 4, 437–447, http://dx.doi.org/10.1080/00223131.2014.873360

ARTICLE

JSFR key technology evaluation on fuel handling system

Yoshitaka Chikazawaa∗, Atsushi Katoha, Hiroyuki Obatab, Masayuki Uzawac, Kazuhiro Kogad and Ryo Chishiroe

aJapan Atomic Energy Agency, 4002 Narita, Oarai, Higashi-ibaraki-gun, Ibaraki 311-1393, Japan; bJapan Atomic Power Company,4002 Narita, Oarai, Higashi-ibaraki-gun, Ibaraki 311-1393, Japan; cMitsubishi FBR Systems, 2-34-17 Jingumae, Shibuya, Tokyo,Japan; dFuji Electric, 1-1, Tanabeshinden, Kawasaki, Kawasaki, Japan; eKawasaki Heavy Industries, 1-14-5, Kaigan, Minato-ku,

Tokyo, Japan

(Received 1 August 2013; accepted final version for publication 4 December 2013)

A simplified fuel handling system design for the demonstration Japan sodium-cooled fast reactor (JSFR)has been proposed. Fast Reactor Cycle Technology Development project phase I results of key technologyevaluations on a pantograph fuel handling machine (FHM), a fuel transfer pot with two core componentpositions, dry spent fuel cleaning and minor actinide-bearing fresh fuel shipping cask are summarized. Afull-scale FHM mockup has been fabricated and tested in the air accumulating performance and seismictolerance data. A mockup fuel transfer pot with fins and chromium carbide coating has been fabricatedand tested with sodium accumulating heat transfer performance data. Several sodium cleaning tests using adummy subassembly has been conducted accumulating cleaning performance data. For fresh fuel shippingcask, a design tool for evaluation of heat transfer capability has been developed and a helium gas caskshows cooling capability of minor actinide-bearing fresh fuel. Those experimental and analytical effortshave shown that key technologies to develop simplified fuel handling system arematured enough to proceedlarge-scale sodium experiments and conceptual design study for the demonstration JSFR.

Keywords: sodium-cooled reactor; fuel handling system; fuel handling machine; design

1. Introduction

In 1999, the Feasibility Study on CommercializedFast Reactor Cycle Systems (FS) had been initiated [1].Surveying various fast reactor concepts like sodium-cooled reactor, gas-cooled reactor, heavy metal-cooledreactor and water-cooled reactor with various fuellike oxide, nitride and metal, the FS concluded toselect a mixed oxide fuel sodium-cooled reactor namedJapan sodium-cooled fast reactor (JSFR) as a referenceconcept [2]. Succeeding the FS, the Fast Reactor CycleTechnology Development (FaCT) project is pursuingcommercialization of fast reactor cycle system by 2050under cooperation of MEXT (Ministry of Education,Culture, Sports, Science and Technology), METI (Min-istry of Economy, Trade and Industry), utilities, vendersand JAEA (Japan Atomic Energy Agency). As resultsof the FaCT phase I, the key technologies for commer-cialized JSFR with 1500 MW electric output have beenevaluated [3]. The 10 technologies high burn-up core,safety enhancement, compact reactor vessel, two-loopcooling system using high chromium steel, integratedintermediate heat exchanger/pump component, reliable

∗Corresponding author. Email: chikazawa.yoshitaka@jaea.go.jp

steam generator, natural circulation decay heat removalsystem, simplified fuel handling system (FHS), contain-ment vessel made of steel plate reinforced concrete, andadvanced seismic isolation system have been confirmedto be ready for the phase II development, in whichconceptual design of demonstration JSFR with 750MW electric output and large-scale demonstrationexperiments are involved.

As for the FHS, the JSFR adopts a simplified FHSwith ex-vessel storage tank (EVST) instead of evolu-tional systems without an EVST based on an FHSsurvey study [4]. The result of the survey study hasindicated that the construction cost of the evolutionalsystems without EVST do not reduce the constructioncost dramatically, which is mainly due to additionalsafety measures required higher decay heat handling ingas atmosphere and separated fresh and failed fuel stor-age. From an economical point of view, a longer plantoutage of the evolutional systems offsets its advantageof the lower construction cost. On the basis of theresults of this comparative study, JSFR has selected theFHS with an EVST. In the FaCT phase I, research and

C© 2014 Atomic Energy Society of Japan. All rights reserved.

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Table 1. Design conditions for JSFR FHS.

Items Value

Electric/thermal output 750/1765 MWNumber of driver fuel SA 274Number of blanket fuel SA 66Number of control rod SA 27Number of batch 6SA pitch 206 mmSA length Approx. 4.5 mSA weight 690 kgOperation cycle 18 monthsSA decay heat after 17 days 35 kWSA decay heat after EVST 10 kWFresh SA decay heat 2.6 kW

development (R&D) has been conducted to evaluatefeasibility of the simplified FHS. This paper providesdescription of the preliminary conceptual design of thedemonstration JSFR FHS and evaluation results onkey technologies in the simplified FHS.

2. System design

The preconceptual design of the FHS has been con-ducted based on the 750MWdemonstration JSFR [5,6].The design conditions are shown in Table 1. The JSFRcore is installing minor actinide (MA) and low decon-tamination fuel considering reduction of environmen-tal burden [7]. For the demonstration JSFR, fuel will bereprocessed from light water reactor (LWR) spent fuel.Various LWR-to-FBR (fast breeder reactor) transitionfuels have been investigated, considering various LWR,

burn-up, and cooling conditions [8–10]. The FHS designconditions have been identified to cover the wide rangeof LWR-to-FBR transition fuels. Dimensions of the fuelsubassembly (SA) for the demonstration of JSFR are thesame of the commercialized JSFR. The batch numberof 6 is slightly different from that of FBR multirecycleequilibrium core of 4. Operation cycle is 18 months thatis shorter than 26 months of the FBRmultirecycle equi-librium core. The maximum decay heat of spent fuel SAafter 17 days from reactor shutdown, which means de-cay heat during refueling is evaluated to be 35 kW withdesign margin. The spent fuel storage in EVST duringone operation cycle and the reduced decay heat is lessthan 10 kW to handle in the gaseous area. Since JSFRhandle MA-bearing fuel, fresh fuel SA also has certaindecay heat while conventional fresh fuel does not. In theFaCT design conditions with MA content up to 5% inthe homogeneous core, the maximum decay heat of theJSFR fresh fuel is 2.6 kW.

JSFR has adopted a simple FHS with advancedtechnologies as shownFigure 1. The JSFR in-vessel FHSconsists of a combination of an upper inner structurewith a slit (slit UIS) and a flexible arm type pantographfuel handling machine (FHM) to dramatically reducethe reactor vessel diameter. The FHM is removed dur-ing power operation from the reactor vessel. From thereactor vessel to the EVST, a spent SA which is ac-commodated by a sodium pot is transported by an ex-vessel transfer machine (EVTM) as shown in Figure 2.A two-position sodium pot has been installed for trans-portation of SAs from the reactor vessel to the EVSTto reduce the refueling time and thereby increase plant

Figure 1. JSFR fuel handling system.

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Figure 2. EVTM sketch.

availability. Active cooling is not necessary during thetransportation from the reactor vessel to the EVST sincethe sodium pot provides enough heat capacity. Onlywhen the transportation has malfunction and stuck, thesodium pot cooling system that consists with combi-nation of direct and indirect cooling is activated. TheEVST has enough capacity for full core evacuation toenhance the plant’s in-service inspection and repair ca-pability as shown in Figure 3. It has 431 SA positions

including 84 positions for one refueling campaign, 340for whole core evacuation and 7 for failed fuel. The di-ameter of the EVST is 10.5 m with heat removal capac-ity 9.8 MW. After approximately one-cycle operation,spent fuel SAs are transported to the spent fuel stor-age pool by EVTM with argon gas cooling. During thetransportation to the storage pool, the spent fuel SA iscleaned to remove residual sodium from SA surfaces.The spent fuel cleaning method has changed from the

Figure 3. EVST with capacity for a whole core evacuation.

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conventional water rinse to argon gas dry cleaning toeliminate a facility for SA cleaning and reduce radioac-tive liquid waste. After argon gas dry cleaning at the SAguide tube of the EVST, the SA is transported by EVTMand residual sodium is made to be inert using moist ar-gon gas, at the SA lifter at the entrance of the spentfuel storage pool. The storage capacity of the water poolis 227 to maintain the total SA storage capacity of thenuclear building of 658 including storage capacity for8-year operation, one batch of control rods, a whole coreevacuation and failed fuel. A fresh FHS has been de-signed to accommodate decay heat and radiation fromthe MA-bearing fuel in accordance with JSFR’s coreconcept, transmuting MAs from LWR and containingtrans-uranium elements inside the fast reactor fuel cyclesystem.

Key technologies for the proposed FHS are listed inTable 2. There are four new technologies to be evaluated:flexible arm type pantograph FHM, sodium pot withtwo core component positions, dry cleaning of spentfuel SA, and fresh fuel shipping cask. JSFR installs theflexible arm type pantograph FHM instead of an off-set arm type pantograph FHM in Monju. In the newFHM, positioning of the flexible arm and interactionbetween the FHM-slit UIS in the seismic conditions aremajor issues. For the sodium pot for two core compo-nents positions, cooling capability for two spent fuel SAsand various conditions is selected as a key issue. Forthe dry cleaning of spent fuel SA, performance of drycleaning process, sodium inert process after dry clean-ing, and cladding integrity in the spent fuel pool aremajor issues, since cleaning process is completely dif-ferent from the conventional wet process with waterrinse and the cladding material is changed to the ox-ide dispersion strengthened (ODS) steel. For the freshfuel shipping cask, cleaning performance of the ship-ping cask is selected as a key issue. Since JSFR adoptMA-bearing fuel, cooling and shielding of the fresh fuelcask has to be confirmed, while conventional fresh fueldoes not have to take care those points. In the follow-ing sections, evaluation results of those key points aresummarized.

Table 2. Key technologies in FHS.

Items Main issues

Flexible arm type • Positioning of valuable armpantograph FHM • Seismic tolerance

Sodium pot with twocore componentpositions

• Cooling capability of thesodium pot (two corecomponent positions andsubassembly with inner duct)

Dry cleaning of spent • Performance of dry cleaningfuel subassembly • Sodium inert process

• Integrity of cladding in thespent fuel pool

Fresh fuel shipping caskfor MA-bearing fuel

• Cooling capability of thefresh fuel shipping cask

3. Flexible arm type pantograph FHM

A full-scale mockup of the pantograph FHM hasbeen manufactured to evaluate basic feasibility [11].Major requirements on the FHM are as follows:

(1) Slim structure suitable for UIS slit (400 mmwidth),

(2) Prevention of interact with the UIS,(3) Positioning accuracy within a few millimeter

order,(4) Stiffness against SA insertion/extraction

(25 kN),(5) Short refueling time (30 min per SA),(6) Recovery from abnormal events, and(7) Ease of maintenance and repairing.

A sketch of the FHM mockup and photographs isshown in Figure 4. The experiment was conducted inthe air with a dummy SA. The gripper mechanism is in-stalled a self-positioning adjustment mechanism whichcan cover 30-mm offset. However, considering offsetscaused by rotating plug motion, FHM rotation, SA de-formation due to irradiation/thermal expansion, UISdisplacement and offset of UIS/FHMpositions, the hor-izontal positioning accuracy for the mockup FHM inthe air is required to be within 3 mm. For the vertical di-rection, the limit positioning accuracy is set to avoid in-teraction of the FHMand the SA. Since the gap betweenthe SA top and UIS bottom is 35 mm, the vertical posi-tioning accuracy requirement is evaluated to be 10 mmtaking into account FHM/SA offsets and SA swelling.The mockup test showed that the FHM can meet po-sitioning accuracy requirements keeping required speedof 2.3 m/min.

For prevention of interaction between the FHM andUIS, seismic analysis has been carried out using Femapwith NX Nastran Ver.9.3.1. Limit of seismic displace-ment of the FHM is evaluated to be 20 mm in the hori-zontal direction taking into account UIS displacement,offsets and thermal expansion. And the vertical limitdisplacement is evaluated to be 15 mm preventing in-teraction between SA and FHM. The seismic analysisresult with solid hexagonal meshes on the design baseseismic condition shows that the maximum displace-ment of 19.6 mm and 5 mm in horizontal and verticaldirection, respectively, meeting the requirements. Figure5 shows stress distribution. The maximum stress is eval-uated to be 131 MPa that is lower than the design limitof 304SS yield stress at 200◦C of 144 MPa.

For recovery from the abnormal events such as FHMarm stuck, comprehensive survey on initiating malfunc-tion has been conducted and proper recovery measureshave been listed. The most severe event is gripper mal-function holding SA, since the FHM have to delatch SAbefore extraction. In those cases, a device to delatch theSA forcedly from the FHMgripper will be inserted fromthe top of the reactor vessel plug [12].

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Figure 4. Full-scale mockup of pantograph FHM.

4. Sodium pot with two core component positions

During refueling spent fuel SAs accommodated inthe sodium pot are transported from the reactor vesselto the EVST. The JSFR sodium pot has two core com-ponent positions to reduce refueling time. In the nor-mal refueling operation, active cooling is not necessary,since the sodium pot has enough heat capacity. Whenthe sodium pot stuck at the reactor vessel guide tube,active cooling system is activated. The cooling capac-ity of the sodium pot for the demonstration JSFR is35 kW. To evaluate cooling performance of the sodiumpot, a mockup was fabricated and cooling performancewas tested [13]. The fabricated mockup pot is shown inFigure 6. As a result of the fabrication tests, fin machin-ing had no technical issues, and the high velocity oxygen

Figure 5. Stress with design base seismic conditions [11].

fuel thermal process was selected because it was foundto be more suitable for coating on the rather compli-cated shaped surface such as fin than the detonation pro-cess. Properties of the chromium carbide coating such ashardness, thermal conductivity, and thermal expansioncoefficient were obtained.

Heat transfer performance tests using the mockuptransfer pot have been carried out. The experimental ap-paratus, simulating the most severe condition of stop-page of the transfer pot in the guide tube on the wayfrom the reactor vessel, is composed of the test pot andguide tube, whose cross section including fin configura-tions is full-scale to confirm the effect of fin and coat-ing performance in actual condition. The experimentalresults of emission cooling performance are shown inFigure 7 [13]. Those experimental results are categorizedinto three groups from the viewpoint of surface condi-tions of the pot and guide tube as follows:

Case 1: Dry pot and dry guide tubeCase 2: Sodium immersed pot and dry guide tubeCase 3: Sodium immersed pot and guide tube (hypo-

thetical)

For Case 1, the emissivities of the pot and guidetube are evaluated to be 0.5 and 0.5, respectively. Case2 shows results after sodium immersion. In Case 2, thecooling performance is as well as Case 1, since sodiumon the pot surface is evaporated at first. As the thermaloutput of the pot grows, the emission from the potis observed to reduce due to deposition on the guide

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Figure 6. Fabrication of sodium pot mockup.

tube surface. The evaluated emissivities of the pot andguide tube are 0.5 and 0.3 in this case. The Case 3 is ahypothetical case with sodium on the guide tube, sincethe guide tube in the reactor vessel does not have changeto contact with sodium directly. The emissivity of theguide tube is evaluated to be 0.1 in Case 1. At this stage,the sodium pot cooling system has been designed withthe conservative emissivity of the hypothetical Case 3.

A three-dimensional (3D) analysis model using CFXcode for heat transfer evaluation of the JSFR fuel

Figure 7. Experimental results of emission cooling [13].

transfer pot was developed [14]. The heat transfer modelinside the pot has been validated using the CCTL-CFRexperiments [15]. The heat transfer model outside thepot has been validated using the mockup pot experi-mental results. Using the developed 3D model, coolingperformance of the pot has been evaluated. The cal-culation results show that the fuel transfer pot can becooled by combination of indirect cooling with air anddirect cooling with argon gas even with the conservativeemissivity. One of calculation cases with two SAs with22.4 kW each is shown in Figure 8 [14]. For a simplerdesign tool, a two-dimensional (2D) analysis model us-ing ZEPYRUS code was also developed and validatedby the 3D analysis model [14]. The sodium pot for thedemonstration JSFR has been evaluated. In the calcula-tion, the air flow rate at 60◦C for the indirect cooling is20 m3/min-normal and the argon gas flow rate at 150◦Cfor the direct cooling is 8 m3/min-normal. The resultsshow that the sodium temperature at the center of theSAs is lower than the limit 600◦C as shown in Figure 9.

5. Dry cleaning of spent fuel SA

In JSFR, an advanced spent fuel cleaning process isadopted and a spent fuel SA is stored in the water pooldirectly without canning. A concept of the advancedspent fuel cleaning, so-called dry cleaning is shown in

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Figure 8. 3D evaluation on direct-indirect combination cool-ing [14].

Figure 10. In the dry cleaning method, a special facil-ity for spent fuel cleaning like the fuel cleaning facil-ity in Monju is unnecessary. The spent fuel dischargedfrom the EVST is hold at the EVST guide tube (a tubethrough which the EVTM accesses to the EVST) and

Figure 9. Evaluation on the sodium pot for demonstrationJSFR.

argon gas circulation by the argon gas cooling system isprovided during a certain period to blow away sodiumon the spent fuel SA. After the gas blow, the SA is trans-ported to the water pool guide tube by the EVTM. Andat the guide tube, residual sodium on the spent fuel SA isinert by moisture argon gas and immersed into the wa-ter pool. Since JSFR spent fuel SAs are stored in thewater pool without canning, a certain amount of resid-ual sodium is acceptable as long as the water pool pu-rification system can handle it. Water conditions of theJSFR water pool is managed by the purification systemand sodium carried into the water pool would be accu-mulated at the purification system. One major feature ofthe new cleaning method is that radioactive liquid wastedue to spent fuel cleaning is reduced because the new

Figure 10. Image of dry cleaning and residual sodium on a mockup SA.

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process is free from spent fuel rinse which cannot avoida certain amount of liquid waste.

Since the JSFR SA has an inner duct to enhancemolten fuel release in case of severe accidents, sodiumdrain from the inner duct is an issue. In the previousstudy, inner duct drain tests using inner duct mock-ups were conducted and drain performance of the innerduct was confirmed. To demonstrate the proposed drycleaning process, a full-scale mockup of a JSFR fuel SAwhich involves fuel pin bundle, wrapper tube and innerduct was manufactured and dry cleaning performancetests after sodium immersion were conducted as shownin Figure 10. The experimental results showed that theresidual sodium on the mockup SA is less than 200 gafter the cleaning process. Based on the experimentalresults of residual sodium density of each part of themockup SA, amount of residual sodium on the JSFRSA was evaluated as shown in Table 3 taken into ac-count uncertainty and design margin [16]. The residualsodium of the SA is evaluated to be approximately 400 g.After dry cleaning, the spent fuel SA is transported tothe water pool guide tube and the residual sodium ismade inert by humid argon gas and steam. Experiencesin Joyo and Monju showed that duration of the sodiuminert process would depend on sodium density on spentfuel SAs and the inert process duration would be ap-proximately 25 min. For the JSFR fuel-handling de-sign, the inert process duration is designed to be 30 min

Table 3. Evaluation of residual sodium on cleanedsubassembly.

conservatively based on the Joyo andMonju experiences[16]. From the viewpoint of the FHS operation, two SAsin the EVST are transported to the spent fuel storagepool. The pool water can be maintained less than pH

Figure 11. Fresh fuel shipping cask.

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10 with a proper pool purification system and the ODScladding is thought to be tolerable based on the corro-sion experiments [17].

6. Fresh fuel shipping cask

Fresh fuel shipping is always an issue when asodium-cooled reactor is going to handle MA-bearingfuel that requires shielding and cooling. In the JSFRdesign range, the fresh fuel SA might have 2.6 kWdecay heat per SA. The cladding temperature limits areset to be 395◦C for inert gas environment (core inlettemperature) and 300◦C in the air [18] to prevent creepdamage and oxidation. The JSFR fresh fuel shippingcask adopts helium gas coolant to avoid water contactbefore core loading and to provide better heat removalperformance than other gaseous coolant. A helium gascask with five-SA positions has been designed as shownin Figure 11. Two design evaluation models have been

developed [19]. Cooling performance is roughly evalu-ated by the ABAQUS code with a 3Dwhole cask model.The conservativeness of the whole cask calculation wasconfirmed by the fact that the cladding temperatureevaluated by the detailed SA calculation by Star-CDshowing the detail SA calculation, provided lowercladding temperature than that of the whole cask anal-ysis. Figure 12 shows calculation results of a cask withtwo SAs of 2.6 kW decay heat each. In the 3D wholecask model, the maximum cladding temperature isevaluated to be 367◦C, while the maximum temperaturefrom the detail 2D calculation is 351◦C. Those analysesshow the 3D whole cask model can provide conserva-tive evaluation on the maximum cladding temperature.Relation between accommodated SAs and maximumdecay heat has been evaluated as shown Figure 13. Theresults show that the proposed helium gas cask canhandle SAs with decay heat up to 2.2 kW/SA. Evenwith higher decay heat SAs, the cask can manage them

Figure 12. Fresh fuel temperature calculation.

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Figure 13. Cooling performance of fresh fuel shipping cask [19].

by reducing SA accommodations from five to a few. Itmeans that all MA-bearing fresh fuel in the FaCT deignrange can be handled the proposed helium gas cask.

7. Conclusions

A simplified FHS for the demonstration JSFR hasbeen proposed. The FaCT phase I study concluded thatthe JSFR FHS is feasible. R&D on the flexible arm-type pantograph FHM, sodium pot, and fresh fuel caskshows the feasibility of each technology. A full-scaleFHM mockup has been fabricated and tested in the air,accumulating performance and seismic tolerance data.The results from the mockup experiment and analysishave shown that the positioning accuracy of the flexi-ble arm and the seismic tolerance meet requirements. Amockup fuel transfer pot with fins and chromium car-bide coating has been fabricated and tested with sodiumaccumulating heat transfer performance data. Based onthe experimental results, design evaluation tools havebeen developed and validated. And the cooling perfor-mance of the sodium pot with two core componentspositions has been confirmed. Several sodium cleaningtests using a dummy SA has been conducted accumu-lating cleaning performance data. Based on the exper-iments, performance of the cleaning process has beenconfirmed taking into account uncertainty. For corro-sion in the spent fuel pool, integrity ofODS cladding hasbeen confirmed based onmaterial experiments. For freshfuel shipping cask, a design tool for evaluation of heattransfer capability has been developed and a helium gascask shows cooling capability of MA-bearing fresh fuel.Those experimental and analytical efforts have shownthat key technologies to develop simplified FHS arematured enough to proceed large-scale sodium experi-ments and conceptual design study for the demonstra-tion JSFR.

AcknowledgementsThis paper includes results of “Technical development pro-

gram on a commercialized FBR plant” entrusted to JAEAby the Ministry of Economy, Trade and Industry of Japan(METI). And the present study includes the results of “De-velopment of Fuel Handling System” entrusted to The JapanAtomic Power Company (JAPC) by the Ministry of Edu-cation, Culture, Sports, Science and Technology of Japan(MEXT).

List of acronyms

EVST ex-vessel storage tankEVTM ex-vessel transfer machineFBR fast breeder reactorFHM fuel handling machineFHS fuel handling systemJSFR Japan sodium-cooled fast reactorLWR light water reactorMA minor actinideODS oxide dispersion strengthenedSA subassemblyUIS upper inner structure

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[12] Katoh A, Hirata S, Chikazawa Y, Uto N, Obata H,Kotake S, Uzawa M. Development of the JSFR fuelhandling system and mockup experiments of fuel han-dling machine in abnormal conditions. Paper presentedat: Proceedings of ICAPP2010; 2010 Jun; San Diego,CA.

[13] Chikazawa Y, Katoh A, Hirata S, Obata H. Heat trans-fer experiments on fuel subassembly transfer pot forJSFR. J Nucl Sci Technol (to be submitted).

[14] Chikazawa Y, Hirata S, Obata H. Development of de-sign evaluation tools for the JSFR Fuel transfer Pot.Nucl Eng Des (to be submitted).

[15] Toda S, Ieda Y, Kamide H, Komatsuzaki K. Study ofheating/cooling effects on transverse temperature distri-bution in a FBR subassembly 1994. Paper presented at:Proceedings of Fall Meeting of Atomic Energy Societyof Japan D37; Sep 1994; Sapporo, Japan (in Japanese).

[16] ChikazawaY,KatohA,ObataH.Development of argongas cleaning for sodium-cooled reactor spent fuel. J NuclSci Technol. 2013;50-10:988–997.

[17] Narita T, Ukai S, Kaito T, Ohtsika S,MatsudaY.Watercorrosion resistance of ODS Ferritic-Martensitic steeltubes. J Nucl Sci Technol. 2008;45-2:99.

[18] Kaito T, Narita T, Ukai S. High temperature oxida-tion behavior of ODS steels. J Nucl Mat. 2004;329-333:1388.

[19] Katoh A, Chikazawa Y, Obata H. Feasibility study onshipping cask for JSFR fresh fuel contained minor ac-tinide. Nucl Eng Des. 2012:247;98.

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